Which of the following statements regarding profit planning is not true?

To estimate the amount of operating income at different levels of unit sales, you can multiply the number of unit sales above the break$-$even level of unit sales by the unit contribution margin.

If a company's fixed costs increase by $$100,000$ per year, then the sales needed to break even will generally increase by more than $$100,000.$

Managers can use the cost$-$volume$-$profit model to evaluate how sensitive future profits are to changes in selling prices or the sales mix.

The lower the contribution margin ratio, the lower the amount of sales revenue needed to cover the company's fixed costs.